A wide variety of calendars and calendar-diary combination are known. Such calendars include annual calendars and multi-year calendars provided with sequential displays to properly indicate the months, years, weeks and days and in some instances even make provision for other functions such as the diarying or logging of particular information, such as birthdays, anniversies or the like or other important information.
U.S. Pat. No. 1,415,883, for example, discloses a multi-year desk or memorandum calendar having a separate sheet for each day of the year. Beside the month and day date, e.g., "AUG. 5", each sheet includes a list of days of the week and corresponding year, e.g., "Friday 1921"; "Saturday 1922"; etc., so that each sheet may be used several times for successive years. A portion of each page is provided for the entry or diarying of information.
A perpetual calendar is disclosed in U.S. Pat. No. 1,848,634 which includes a base member foldable transversely at two points dividing the same into three 2 sided panels, the faces of each panel carrying two month designations and associated week day designations "S, M, T, W . . . ", but no numerical date. A separate flexible numerical date-carrying strip is provided which has printed on its face a matrix of numbers in rows and columns, so arranged that when properly positioned on a selected panel of the base member, the combination correctly displays the date sequence for the selected month. The calendar also includes a transverse endless coverband cooperating with the numerical date strip to conceal certain invalid numerals when desired and to provide support functions. No functions other than a perpetual calendar are apparent.
U.S. Pat. No. 2,027,286 discloses a calendar date sheet in the form of a folded, U-shaped sheet for three months imprinted on each face of each panel of the U so that any set of 3 months can be displayed by rotating the U configuration 180 degrees and/or turning it inside out. The upper ends of the U are releasably held together by a folded clamping member. The only additional functions apparent in this reference are the provisions of space for perpetual advertisements and for annotations.
Another perpetual calendar is disclosed in U.S. Pat. No. 2,340,153 which provides a calendar which in its pattern of association of the days of the week with days of the month presents the appearance of an ordinary calendar, whether showing a single month of the current year or a sequence of months. Unlike an ordinary design, this calendar does not expire at the end of a year or other period. Without recourse to any external data, the calendar can be set perpetually. Structurally, the calendar takes the form of twenty-one cards, seven of which are year cards, referred to as masks and fourteen of which are month-cards, twelve of which represent the twelve months of any year other than leap years and the thirteenth and fourteenth of which represent January and February of leap years only. When the proper year card is aligned over the proper month card, the opening in the year card exposes the correct number of days for that month and year, in sequence, and the correct designation of the days of the week - the visible effect being that of the ordinary calendar. Multiple functions are not apparent although there is sufficient border space for annotations.
Another arrangement known in the field of calendars is a constant reminder memorandum device of the type disclosed in U.S. Pat. No. 4,218,077. The calendar includes chart means for the recording of special events and means for facilitating retrieval of such recorded events. In a preferred form, a single chart serves as a reminder of events and enables the user to see events for a period of six months at one time; in an expaneded form six charts are utilized to provide more space for recording events to be remembered.
Finally, in U.S. Pat. No. 4,488,366, there is disclosed a calendar with a combined display of consecutive months which optionally includes a support or cover means. The calendar structure includes linking apparatus for displaying in a linked and continuing fashion, time sequences shown on separate pages thereof. The individual pages are provided with specific hinging structures to permit simultaneous viewing of the last portion of one month and the first portion of the next month, so that a continuous display is provided for linked time sequences notwithstanding the fact that such sequences are provided on separate pages.
While some of the foregoing prior art calendars also serve as a calendar/memo pad or diary, none of them provide, at the same time, a storage function for storing sheet material such as notes, cards, memos, invoices and the like. Nor do they provide a calendar arranged for the easy transferral of notations such as birthdates, from one year to the next and in which the backs of the calendar panels are arranged to facilitate annotations and the making of a complete log. There exists, therefore, a need for calendars and/or reminder devices which provide such features and the present invention fulfills such a need.